great food, fun atmosphere. bj's has exceptional food- especially their pizza which is chicago style. however, everything i've had from salads, sandwiches and nachos are all amazing. i've never left 100% content- and i've always been full.
they have a huge bar, in which they also brew their own beer, most of which are really good. i would recommend ordering the beer sampler for your first time- which you can pick 4-5 beers (about 5 oz each) so you can try them all. if you like cocktails, those are also great, but slightly pricey in comparison to the food/other drinks.
the atmosphere is similar to a sports bar. it is casual, but cool.
only fall back is at dinner time, the wait is generally 45-65 minutes.
when you go to bjs- you must- order the pizzookie, their world famous dessert. it is a cookie on a skillet with icecream on top, and it is the best in class.
as far as service, i have had absolutely incredible waitresses/waiters even during peek hours. that being said, there has been several times where the service has sucked, even during off times when the server didn't have any other tables. so service, overall, is a toss-up in both the bar area and the restaurant.